SELECTIVE REDUCTION BY NORADRENALINE AND 5-HYDROXYTRYPTAMINE OF NOCICEPTIVE RESPONSES OF CAT DORSAL HORN NEURONS
SELECTIVE REDUCTION BY NORADRENALINE AND 5-HYDROXYTRYPTAMINE OF NOCICEPTIVE RESPONSES OF CAT DORSAL HORN NEURONS
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DOI：
10.1016/0006-8993(78)90809-0
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发表时间：
1978-01-01
期刊：
影响因子：
2.9
通讯作者：
GRIERSMITH, BT
中科院分区：
文献类型：
--
作者：
HEADLEY, PM;DUGGAN, AW;GRIERSMITH, BT
选择性降低伤害性反应4 0 L I 7部分选择性降低伤害性反应14 4 7 3非选择性降低两种类型的反应5 I 0 4 4无作用0 I 0 4兴奋效应0 3 0 3总计23 18 22 21当NA射入SG时，NA相对选择性地减少伤害性反应，而对非伤害性反应几乎没有影响(见表I和图1)。这种选择性还原所需的NA的低电流(平均39nA，6nA)与5-羟色胺(见下文)、吗啡4和甲硫氨酸脑啡酰胺5所需的较大电流形成鲜明对比。NA的作用过程与先前报道的甲硫氨酸脑啡肽3，5的作用过程相似，即4-10分钟达到最大作用，5-15分钟恢复。在SG内喷射5-羟色胺也降低了伤害性反应(见图1)，但与NA的不同之处在于选择性减少(表I)和需要更大的喷射电流(平均140~12 nA)。对于3个细胞，5-羟色胺具有渐进而持久的兴奋效应，并伴随着对皮肤刺激反应的不同影响。NA在其中两个细胞上进行了测试，并选择性地降低了这两个细胞的伤害性反应。5-羟色胺与去甲肾上腺素的不同之处还在于伤害性反应减少后所需的恢复时间延长(见图1)：14次测试中有8次恢复需要超过20次雨。与我们之前的实验一样，在SG中注入4，5种氨基酸对神经元的反应几乎没有影响。因此，对于t1神经元，GABA(170±12nA)对7神经元的放电没有影响，而对3细胞和L细胞则分别有最小的抑制和兴奋作用。同样，乙酰胆碱(193±4nA)对7个细胞的反应几乎没有影响。
Selective reduction of nociceptive responses 4 0 l I 7 Partially selective reduction of nociceptive responses 14 4 7 3 Non-selective reduction of both types of response 5 I 0 4 4 No effect 0 I 0 4 Excitatory effect 0 3 0 3 Totals 23 18 22 21When ejected in the SG, NA was relatively selective in reducing nociceptive responses whilst there was little or no effect on non-nociceptive responses (see Table I and Fig. 1). The low current of NA required for this selective reduction (mean 39 nA 6 nA SEM) contrasts with the higher currents {> 100 nA) required for 5-HT (see below), morphine 4 and methionine enkephalin amide 5. The time course of the action of NA was similar to that previously reported for methionineenkephalin amide 3, 5, namely 4-10 min for effects to become maximal and 5-15 min for recovery. 5-Hydroxytryptamine, ejected in the SG, also reduced nociceptive responses (see Fig. 1), but differed from NA in that selective reduction occurred less frequently (Table I) and larger ejecting currents were needed (mean 140~ 12 nA). With 3 cells 5-HT had a gradual and long-lasting (> l0 min) excitant effect; this was accompanied by variable effects on the responses to skin stimuli. NA was tested on two of these cells and selectively reduced the nociceptive responses of both. 5-HT also differed from NA in the prolonged recovery time required following the reduction of nociceptive responses (see Fig. 1): with 8 out of 14 tests recovery took more than 20 rain. As in our previous experiments 4, 5 amino acids administered in the SG had little or no effect on neuronal responses. Thus with t 1 neurones, GABA (170±12 nA) had no effect on the firing of 7, while minimal depression and excitation were seen with 3 cells and l cell respectively. Similarly, acetylcholine (193±4 nA) had little or no effect on the responses of 7 cells.